1978 07 20 Nature - Vol 274 - Vera Rich

Magazine Overview

Title: Nature
Issue: Vol. 274
Date: 20 July 1978
Publisher: Macmillan Journals Ltd
Country: United Kingdom
Language: English
ISSN: 0028-0836
Price: $01.00

This issue of Nature features an article titled "The 70-year-old mystery of Siberia's big bang," by Vera Rich, discussing the enduring enigma of the 1908 Tunguska event.

The 70-year-old mystery of Siberia's big bang

Seventy years prior to the article's publication, on July 1, 1908, a significant event occurred in Siberia, initially noted by a Miss Katharine Stephen in a letter to The Times. The nature of the light and explosion observed remained unexplained, with early suggestions including aurora borealis or a volcanic eruption. News from Siberia was restricted during the Tsarist era, and local reports were delayed, preventing wider awareness.

One pre-1914 story mentioned an explorer finding a "lake" of solid diamond created by a meteorite impact on a coal seam, which was subsequently lost. The first attempt to locate the site was made in 1927 by Leonid A. Kulik, who led an expedition to Siberia. The penetration of Siberia and its integration into the Soviet economy was symbolically important to Russian leaders, many of whom had experienced exile there. The region's unexploited wealth was well-known, and a giant meteorite was seen as a potential economic asset.

Kulik's expedition, after several days of reindeer travel from the Stony Tunguska river, discovered not a meteorite but a scene of devastation: flattened trees with small, branchless plantations at the apparent epicentre. The "meteorite" itself was never found. The wrecked terrain presented a mystery. A parallel was drawn in 1945 to the blast phenomena observed at Hiroshima and Nagasaki, leading to suggestions that the Tunguska disaster might have originated from a similar cause. Local accounts of reindeer suffering from mysterious scabs and tree-ring evidence showing accelerated growth rates since 1908 (also characteristic of nuclear-bombed cities) further fueled this hypothesis. The "pillar of fire" recollected by natives was likened to a mushroom cloud, reinforcing the popular imagination of Tunguska as a nuclear explosion.

The article questions whether these phenomena are exclusively characteristic of nuclear devices or could be attributed to any powerful explosion. It notes that the 'nuclear' hypothesis appealed to many, especially when combined with the idea of a disaster involving an extraterrestrial spacecraft. Explanations for the Tunguska event have been diverse, including a giant ball of ice and snow, ball lightning, antimatter, and a black hole. By 1976, Igor Zotkin of the Committee of Meteorites of the Soviet Academy of Sciences remarked on the multitude of explanations proposed for the Tunguska enigma.

Recent expeditions have focused on vitreous particles found in peat bogs and increased radioactivity in surviving trees. Conventional Soviet opinion, supported by figures like Academician Georgii Petrov, Professor Nikolai Vasil'ev, and Vitalii Bronsten, now suggests the explosion was caused by a small comet disintegrating in the atmosphere, with blast patterns supporting an aerial explosion. However, Professor Feliks Zigel of the Moscow Aviation Institute, based on eyewitness accounts from 15-20 years after the event, maintains that the object changed direction twice before impact, suggesting it was a UFO.

Alekesi Zolotov, described by Moscow radio as "another noted investigator," firmly adheres to his own explanation of a nuclear explosion, possibly of extraterrestrial origin. Zolotov's persistent involvement in discussions of the Tunguska problem, despite his theories being considered bizarre by scientific establishments, is noted as surprising within the Soviet academic system, which emphasizes procedure and peer review. His academic background is described as obscure, with one physicist suggesting he was originally an oil technologist co-opted for his knowledge of local terrain.

To commemorate the 70th anniversary of the event, another expedition was planned for the current year. A Tass radio commentary expressed hope for new facts to be elicited in scientists' laboratories, but the article concludes that, if past expeditions are indicative, the event may continue to generate further legends.

Recurring Themes and Editorial Stance

The article maintains a critical and analytical stance, examining various theories surrounding the Tunguska event without definitively endorsing any single one. It highlights the enduring mystery and the diverse range of explanations proposed over seven decades, from scientific hypotheses involving comets and meteorites to more speculative ideas like UFOs and nuclear explosions. The editorial stance appears to be one of scientific inquiry, acknowledging the complexities and the persistent appeal of the Tunguska enigma to both scientific and popular imagination. The article implicitly encourages further investigation while cautioning against the proliferation of unsubstantiated theories.